I use DolarPalermo (look them up on Instagram) for USDT to USD cash.
They charged me 1.8% last time, but there have been months where the charge is as low as 0.5%. (Recently the fee has been high due to the cash part of the blanqueo).
They also charge $5k delivery.
But the service is outstanding, they deserve it. I order via WhatsApp and it arrive within a few hours and, if request it, they guarantee me the blue cara grande notes.
I believe they do USDT for pesos, but last time I enquired the minimum amount was $500.
There is also ExpressCoin in Plaza Serrano, they exchange USDT for pesos cash in person, but charged 3% last time and the dollar blue rate not the p2p crypto rate.